The Botany of Iceland - 01.12.1930, Side 24

14
H.M0LHOLM HANSEN
Vestfirðir 16.0, the Norlh Country 16.6, and the East Country 18.0.
There is thus an unbroken rise in the chaniaephyte percentage from
the South Country, whose chamaephyte percentage corresponds to
that of the whole country, towards the west and north, until it at-
tains its highest value, 18.0, in the east. It is difficult to ascertain
what climatic factor causes this rise, and more probahiy we may
assume that not one but many factors are determining. The physical
factor which varies parallelly with the variations in life forms is
the annual mean temperature of the oceanic surface water. Thís
as we showed above, was closely correlated to the amount of Gulf
Stream water and Polar water at the coasts. The variation in other
climatic conditions, whether it be in the air temperature, number
of days with frost, the coldest or warmest month, amount of pre-
cipitation, number of days with precipitation, days with snow, frost
or gales, does not agree nearly so well with the variation in life
form as the temperature conditions of the surface water.
The correlation of the biological peculiarities of the flora, more
especially of the chamaephyte percentage, and the current conditions
of the adjacent seas is likewise confirmed in the surrounding countries.
Table 2 gives the biological spectra for West and East Greenland,
calculated on the basis of the llora lists given by Ostenfeld (1926).
Tlie west and east coasfs of Greenland are each divided into 8
minor corresponding areas. The east coast is washed by a Polar
current coming from the north, the Greenland Current, while the
west coast is washed by a current coming from the south. In ac-
cordance herewith we find that the chamaephyte percentage in the
individual, corresponding, minor areas as well as for the two coastal
tracts as a whole is highest in the east, lowest in the west. The
table shows the composition of the biological spectra. Starting from
the number of species, the chamaephyte percentage for the whole
of East Greenland is 25.2, for West Greenland 21.6. Starting from
the points sum, the ratio will be 28.6 to 25.2. Only South Green-
land has a chamaephyte percentage lower than 20, viz. 18.6.
If we pass over to the west coast of Baffin Bay and Davis Strait,
we find that a current from the north, the Labrador Current, flows
along the eastern coast of Baffin Land, and according to Raunkiær
(1908), the chamaephyte percentage for Baffin Land is 30, while
for the whole of West Greenland it was only 21.6.
Passing from Iceland towards the east, we find the west coast
of Norway washed by the warm Gulf Stream, and here, as a matter